configs: Use MmioVirtIO for disk image in baremetal.py

The baremetal platform is the platform we use for running
user supplied binaries on baremetal hardware.
(simply put, it runs provided binaries without adding
a gem5 bootloader)

Some layers of this software stack might not have a pci driver.
This might be the case for firmware images like edkII
which needs to use a block device to extract the bootloader
and/or the kernel image. Those can use the memory mapped
(in host domain) virtio block device which is already
part of the VExpress_GEM5 platforms

Change-Id: I9c6ba7e1b4566a3999fd9ba20a2bebe191dc3ef8
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/39995
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Richard Cooper <richard.cooper@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

diff --git a/configs/example/arm/baremetal.py b/configs/example/arm/baremetal.py
index 011883b401adee09f242439dda31470512a68abb..29e9b48fd9bfa2944e1e3bdcc7a93475432b4d8e 100644 (file)
--- a/configs/example/arm/baremetal.py
+++ b/configs/example/arm/baremetal.py
@@ -1,4 +1,4 @@
-# Copyright (c) 2016-2017,2019-2020 ARM Limited
+# Copyright (c) 2016-2017,2019-2021 ARM Limited
 # All rights reserved.
 #
 # The license below extends only to copyright in the software and shall
@@ -113,24 +113,13 @@ def create(args):
             cmd_line = " ".join([ object_file ] + args.args)
         )
 
-    # Add the PCI devices we need for this system. The base system
-    # doesn't have any PCI devices by default since they are assumed
-    # to be added by the configurastion scripts needin them.
-    pci_devices = []
     if args.disk_image:
         # Create a VirtIO block device for the system's boot
         # disk. Attach the disk image using gem5's Copy-on-Write
         # functionality to avoid writing changes to the stored copy of
         # the disk image.
-        system.disk = PciVirtIO(vio=VirtIOBlock(
-            image=create_cow_image(args.disk_image)))
-        pci_devices.append(system.disk)
-
-    # Attach the PCI devices to the system. The helper method in the
-    # system assigns a unique PCI bus ID to each of the devices and
-    # connects them to the IO bus.
-    for dev in pci_devices:
-        system.attach_pci(dev)
+        system.realview.vio[0].vio = VirtIOBlock(
+            image=create_cow_image(args.disk_image))
 
     # Wire up the system's memory system
     system.connect()